How much BHP am I likely to gain from twin 40s?

[sr nova boi]

Hi all, i am currently fitting twin webber 40s to my 1991 1.4 sr along with a magnex full stainless exhaust, facet fuel pump and new downpipe. I am just curious as to what kind of power increase this will give me roughly? cheers, rob

[Stuart]

std cam and head?

I'd say about 5-10bhp if you are lucky

[sr nova boi]

At the moment yes, but will be fitting a fast road cam to it asap.

[Mike]

Might aswell add an aftermarked exhaust manifold in to the flava

[sr nova boi]

I will, Im fitting this lot first but am definately on the look out for one

[wwmnw]

I wouldn't bother til you have all the other power increasing parts tbh.

[nova_saloon]

agreed otherwise thoose things are going to through all that precious petrol away!

[Nobby]

yup carbs drink fuel like a barsteward mine does between 20-24mpg :(

[bmw156]

agreed otherwise thoose things are going to through all that precious petrol away!

throw lol

[comptoncj]

I got 40mpg out of my 1300, but the noise is addictive and that brought it down to about 10mpg.

[Plug]

and if you put the carbs on then get it set up it will have to be re-adjusted to compensate the other parts (cam,manifold, etc)

[sr nova boi]

thanks for all your posts, ive never been bothererd about mpg to be honest! aslong as they put a smile on my face im happy!

[jimbob-mcgrew]

30 brake if u spray em with vht lol

[sr nova boi]

30 brake if u spray em with vht lol

:confused:

[Royston]

Std 1.3 nova engine 70hp, Sport with carbs 82hp so depending on engine condition @8-12hp

[Royston]

(Sport with carbs & cam 93hp )

[sr nova boi]

Thanks mate, i hope so engine has just touched 80,000 and pulls really well. Will post the dyno readouts and pics when its all done

[Mk1'SR'Dan]

on the subject of predicting power outputs... ive got a C14SE, ive got a 1.3 stage two head (ported and polished, triple angle valve seats, skimmed to comp height, which will go on when its been flushed out and unblocked) twin 40 DCOEs, heat wrapped ashley manifold, bespoke ashley comp exhaust, magnecor 8mm leads, super 4 plugs, 1300 flywheel and it runs on a minimum of 97 octane unleaded...? any ideas anyone?!

[Royston]

on the subject of predicting power outputs... ive got a C14SE, ive got a 1.3 stage two head (ported and polished, triple angle valve seats, skimmed to comp height, which will go on when its been flushed out and unblocked) twin 40 DCOEs, heat wrapped ashley manifold, bespoke ashley comp exhaust, magnecor 8mm leads, super 4 plugs, 1300 flywheel and it runs on a minimum of 97 octane unleaded...? any ideas anyone?!

My 1.3 Sport has a similar build spec - 103hp - flywheel

[Stuart]

on the subject of predicting power outputs... ive got a C14SE, ive got a 1.3 stage two head (ported and polished, triple angle valve seats, skimmed to comp height, which will go on when its been flushed out and unblocked) twin 40 DCOEs, heat wrapped ashley manifold, bespoke ashley comp exhaust, magnecor 8mm leads, super 4 plugs, 1300 flywheel and it runs on a minimum of 97 octane unleaded...? any ideas anyone?!


so youve gone for a smaller valved head..... oops.
Depending on the person setting up and the RR, given its a 1400 on a 1300 head I'd say about 105 at the fly if you are lucky, more like 110-120 if it was a worked 1400 head.

[Mk1'SR'Dan]

its got a standard 1400 head on it at the moment... thought putting the skimmed to buggary 1300 head on would raise the compression up a bit... might get the 1400 head ported then...!

[Mk1'SR'Dan]

cheers stu! are the valves in 1400 heads bigger then?!

[Stuart]

1.4 mpi heads are the 'same' as the 1.6 mpi heads so bigger valves.

[Mint FRST]

Back in the day my 1.4SR with 40's, a 4 brach and Ashley system put ot 105Bhp.

It depends on the person setting them up and also how accurate their rollers are.

I had no problems with Paxo VTRs when they 1st came out...

[Mk1'SR'Dan]

i already eat up VTR's... poxy cheese eating surrender monkeys...!! even with a mere 105 bhp, at 750 kilos makes 140 bhp/tonne, which is 16 more than my mates 07 Mazda RX8... nice! im not too fussed about the actual output really, i wouldnt stick it on the rollers until ive done a bit of bottom end work first... does anyone know how well the standard bottom end will stand up to the 40s and the other bits?

[jas2000000]

You won't get a lot of power out of em on their own. Try bolting them to the engine for best results.

[Mk1'SR'Dan]

cheers for the heads up jas... i had considered that... i am considering doing a degree in motorsport engineering next year so its not like im completely clueless!

[Mk1'SR'Dan]

this is what im bolting them to...

http://www.pngclub.com/forum/showthread.php?t=134543&page=2

[sr nova boi]

So after all that can someone please tell me what VHT is?! lol

[Aragorn]

http://lmgtfy.com/?q=VHT

[Stuart]

http://lmgtfy.com/?q=VHT


lol long time no see and you post that gem!!! Legend!

[Aragorn]

Aye lol.

Folk still messing with these crappy carburettors too i see!

Bruce proved EFI is better with his 150hp 1.6 GTE engine about 5 years ago, and i did all that work wringing more power out of the SPi system but people just dont listen eh?

[Mike]

http://lmgtfy.com/?q=VHT

LMFAO lol lol